One vertex per element, one color per generator, with an edge from x to x·s.
(5,6,8,10)(7,9,11,12)(13,14,16,21)(15,22,23,18)(17,19,25,20)(24,27,28,26)(1,2)(3,4)(5,6)(7,9)(8,10)(11,12)(13,15)(14,18)(16,23)(17,24)(19,26)(20,27)(21,22)(25,28) involution — undirected(2,4)(5,7,8,11)(6,9,10,12)(14,19)(17,25)(18,26)(20,21)(22,27)(24,28)(6,10)(9,12)(14,20)(15,23)(17,25)(18,26)(19,21)(22,27) involution — undirected(15,23)(18,22)(24,28)(26,27) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.